Hydro International’s Stormbloc® geocellular soakaway system has been chosen to manage highway surface water runoff as part of a much-needed development of affordable housing in rural Cornwall.

Background

The North Country development was built for Coastline Housing, a local not-for-profit housing association that owns and manages over 4,000 homes in the county. The first phase of the development was finished in March 2016, with a second phase completed in the summer.

With house prices in Cornwall continuing to be more than 11 times average earnings, many people have been excluded from owning their own homes. The North Country development is one of the housing association’s biggest-ever developments, providing homes for rent, part-buy and part-rent, and is supported by Homes and Community Agency funding.

Challenge

As the ground conditions in Cornwall are usually favourable for infiltration of excess surface water, Cornwall Council promotes the use of soakaways as the preferred option for surface water drainage in the county.

Two soakaways were required to be built to manage surface water from Bassett Road as part of 49-home development in the village of North Country near Redruth, Cornwall. Maintenance and regular inspection were key considerations when choosing the Sustainable Drainage System (SuDS).

Solution

Consultant engineers Nijhuis H2OK Ltd specified Stormbloc® with a Stormbloc® Inspect system to ensure regular inspection and maintenance of the soakaways and comply with local authority highways and drainage guidance.

Stormbloc® Inspect’s inspection chambers and access tunnels in the soakaways are fully integrated within the modular block system to ensure simple installation and connection to the surface water drainage system, as well as easy access for ongoing maintenance.

Benefits

“Percolation testing carried out to CIRIA156/BRA 356 indicated that the ground had good drainage characteristics” confirmed Jan Clark, Development Infrastructure Manager for Nijhuis H2OK. “We specified Hydro International Stormbloc® units as they have been successfully adopted by Cornwall Council on other projects. The council are keen to incorporate improved access and inspection facilities on all drainage features, and the Stormbloc® inspection facility helps in this regard.”

The Bassett Road soakaway system is designed to protect the highway from a 1 in 100 year flood event and includes a 30% climate change allowance. Stormbloc® Inspect can be installed under landscaping or even roadways, while remaining easy to access for inspection and maintenance.